Fluid operated machine and safety control system therefor

ABSTRACT

A fluid operated machine having members for applying pressure to a work piece placed therebetween by an operator, which machine is equipped with safety controls to prevent trapping of the hands of the machine operator, or of another person, between the members during closing of the same upon the work piece. A garment pressing machine employing a valve controlled conduct system with the safety controls included, and without detracting from the numerous operating capabilities required of a garment pressing machine, is employed to illustrate the invention.

Eifilififid States Patent 1 Richterkessing 1 Jan.9,1973

[54] FLUID OPERATED MACHINE AND SAFETY CONTROL SYSTEM THEREFOR [76] Inventor: Frank H. Richterkessing, 1200 Park Hills Drive, Louisville, Ky. 40207 [22] Filed: Jan. 15, 1971 [21] Appl. No.: 106,682

Related US. Application Data [62] Division of Ser. No. 823,722, May 12, 1969, Pat. No.

[52] US. Cl ..91/424 [51] Int. Cl ..F15b 13/042 [58] Field of Search ..9l/424, 425 I [56] References Cited UNITED STATES PATENTS Daly ..9l/425 X Grotewohl ..9 H425 Tanenblatt ..91/424 Primary ExaminerMartin P. Schwadron Assistant Examinerlrwin C. Cohen Attorney-John D. Rice et al.

[5 7] ABSTRACT A fluid operated machine having members for applying pressure to a work piece placed therebetween by an operator, which machine is equipped with safety controls to prevent trapping of the hands of the machine operator, or of another person, between the members during closing of the same upon the work piece.

A garment pressing machine employing a valve controlled conduct system with the safety controls included, and without detracting from the numerous operating capabilities required of a garment pressing machine, is employed to illustrate the invention.

1 Claim, 5 Drawing Figures PATENTEDJAH 9 I973 SHEET 1 OF 4 INVENTOR FRANK H. RICHTERKESSENG Luz M ATTORNEY PAIENTEDJAN 9 I915 SHEET 20F 11 FRANK H.RlCHTERK;E%$\NG ATTORNEY Pmmaum a ma 3.709.101

SHEET 3 OF 4 INVENTOR FRANK nmcmsnxsssme BY XQM/e'hK ATTORNEY PATENTED JAN 9 I975 SHEET l [1F 4 INVENT OR FRANK H. RKZHTERKESSNG BY M/ZW ATTORNEY FLUID OPERATED MACHINE AND SAFETY CONTROL SYSTEM THEREFOR This application is a division of my copending application, Serial No. 823,722, filed May 12, 1969 now issued as Pat. No. 3,640,007.

BACKGROUND OF THE INVENTION Legislation in many jurisdictions now requires the use of safety controls on power operated machines for protecting the hands of an operator, and many patents have been granted on the two-hand safety control concept.

However, the equipping of a machine with such controls frequently imposes limitations upon the full capability of use of the machine, or it may embody a complex or expensive arrangement of parts, and, in some cases, may employ an arrangement that may permit the circumventing of the safety controls by experimentation or by carelessness on the part of the operator.

While the present invention is adapted for use on many types of power operated machines, it is particularly well suited for use on various types of garment pressing machines required to perform a variety of pressing operations on garments of various types. For example, while keeping his hands protected, the operator may be required to effect closing of the press head, either to apply a light or a heavier pressure upon the garment, and either to lock, or not to lock, .the press head in pressure engagement with the garment.

Also, the operator may be required to operate the machine while simultaneously steaming the garment, and to subsequently effect a release of the press head from pressure engagement with the garment. All of these, and other operations, may berequired to be performed by the operator while another personv is present at the machine. Therefore, the present invention has for its object, not only the protection of the operator, but any other person that may be present during such operations.

SUMMARY The invention relates to a safety control system for-a fluid operated machine having a valve controlled conduit system connected to a source of pressure fluid, and to a first actuator or cylinder 23 employed to close cooperative members upon a work piece placed therebetween by an operator. Preferably, a second actuator or cylinder 24, working in conjunction with the first actuator 23, is employed to close the members with a heavier pressure than that effected by the first actuator 23 alone.

The conduit system has a main valve 32 whose position determines whether fluid can or cannot flow to the actuators 23 and 24 the pilot actuator 33 of the valve 32 being connected for pressurization, or for venting to exhaust, as determined by the manual positioning of a manual detent valve 94.

The safety means includes a master valve 40 adapted to receive operating fluid jointly from spaced lefthand and righthand manually operable valves 18 and 19, and to pass fluid from the master valve 40, through a control valve 34 to the pilot actuator 33 of the main supply valve 32, when the control valve 34 is in its operated position. However, the aforesaid flow of fluid from the master valve 40 can be initiated only when the two manually operated valves 18 and 19 are operated within a predetermined time interval of each other, and moreover, the fluid passing from the master valve 40, through the control valve 34, can be attained only when a two way bleed valve 76 in the system is maintained closed; the bleed valve 76 opening when a supplementary safety means 72-73-74-75, primarily for the protection of a person other than the operator, is displaced from a predetermined position, by a person occupying a dangerous position adjacent the cooperative members of the machine.

Among the objectives of the invention are the providing ofa fluid operated machine having means for protecting the hands of the operator, and of other persons present at the machine during operation of the machine; an improved valve controlled conduit system for a fluid operated machine incorporating safety means for the operator, and which system enables the operator optionally to lock, or to prevent locking of, a member upon a work piece with either a light or a heavier pressure of engagement; and an improved garment press having safety means protecting the operator without detracting from the conventional capabilities of the press.

These and other objects and advantages of the invention will become more apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which FIG. 1 is a perspective view of a garment press embodying the invention.

FIG. 2 is a perspective view indicating the relative lo cations of the valves in the conduit system when employed with the press of FIG. 1.

FIG. 3 is a schematic view of the air circuit in the conduit system of FIG. 2 with the valve members identified in accordance with the USAS symbols authorized by the National Fluid Power Association.

FIG. 4 is a cross sectional view of the master safety valve, and

FIG. 5 is a diagrammatic showing the positioning of the safety bar with respect to the buck and head of the press of FIG. 1.

Referring first to FIG. 1, a conventional garment press, with which the present invention is particularly well suited for use, includes the usual base plate 10, buck column 11, head column 12, and yoke 13 pivotally mounted on the head column. Steam connections forming no part of the present invention are provided for the press buck 14 attached to the column 11 and for the press head 15. A table 16 with a protective wall 17 at its rear edge is supported below the buck 14,

and along and below its front edge separate left hand and right hand manually actuated valves 18, 19 respectively (FIG. 2) are located in spaced relation to each other and are interposed in the conduit system of the invention for operation in the manner later to be described.

The yoke 13 normally holds the press head 15 in elevated position by means of a pair'of rods 26 26a connected to the yoke and urged downwardly by counter-balance springs contained in cylindrical shells 20, 21. A suitable oil check 22 is also connected to the yoke 13, and this oil check serves to cushion, or control, the travel of the press head 15 toward and away from the buck 14, so that a smooth engagement of the press head with the buck is effected at the end of its closing travel, and likewise, a smooth arresting of the head movement is effected at the in of its opening travel.

Actuators or cylinders 23 and 24, employed to close the head upon the buck 14, are pivotally mounted upon the buck column 12, and each contains a piston having a piston rod pivotally attached to the yoke 13, to serve a purpose later to appear.

A suitable means 25, carried by the rod 26 extending from the counter-balancing spring, contained within the cylindrical shell 20, to the yoke 13, is adapted to actuate a three way, normally closed cam valve 27, when the head 15 approaches its closed position, as will be described more completely later.

The valve controlled conduit system receives regu lated pressure fluid, for example, air at a pressure of approximately 85PSIG, after passing through a filter 30, and a pressure regulator 31 equipped with an air gage. This regulated fluid pressure is directed to the inlet port of a three way, normally closed valve 32, herein called the main valve, and this valve may conveniently be the three way, normally closed type 250A-3-l0-20, available from Humphrey Products, Kalamazoo, Mich.

The main valve 32 has a pilot actuator 33, and the exhaust port of the main valve 32 is preferably equipped with a suitable silencer or muffler.

The three way, normally open valve 34, herein called the control valve, may conveniently by the three way, normally open Type lA-3-l l-20-60, also available from Humphrey Products.

The control valve 34 has a pilot actuator 35 with a line connection 36 leading thereto from a line connection 46. r

The cylinder, or outlet port of the control valve 34, is connected by line 37 to the pilot actuator 33 of the main control valve 32.

The inlet port of the control valve 34 receives fluid pressure via lines 38a 38 herein called the third conduit, from the actuator or closing cylinder 23, when the piston within the closing cylinder 23 is moved beyond the connection of line 38a thereto, which connection is preferably located at a position wherein the surface of the head 15 is operated to within approximately onehalf inch of the surface of the buck 14. Prior to the movement of the piston, to the aforesaid position beyond the aforesaid connection, theline 38a is vented to exhaust, or atmosphere, through the space above the piston in the cylinder 23.

However, the aforesaid pressurizing of lines 3811-38 is also dependent upon the manual setting of a three way, normally open manual detent valve 94, which valve, when manually set in the position illustrated in FIG. 3 provides a continuous flow connection from the cylinder 23 to the inlet port of the control valve 34. Thus, when the manual detent valve 94 is manually set in its reverse position, the inlet port of the manual detent valve 94, which is connected by lines 38a to the cylinder 23, is blocked, and the cylinder or outlet port of the manual detent valve 94, which is connected by line 38 to the. inlet port of the control valve 34, is then continuously vented to the exhaust port of the manual detent valve, and the outlet port of the manual detent valve may not be pressurized from the connection of line 38a with the cylinder 23. The exhaust port of the manual detent valve is provided with a suitable muffler or silencer.

The exhaust port of the control valve 34 is connected via line 39 to the outlet port in the body B of the master valve 40, and, as will be described more fully later, the outlet port of the master valve 40 is normally connected to exhaust within the master valve, and is transferred from exhaust to pressure, only when the master valve 40 is operated properly by the respective lefthand and righthand manually operated valves 18 and 19, and only while the hands of the operator retain the manually operated valves 18 and 19 continuously actuated after the master valve 40 is operated to transfer its outlet port from an exhaust condition to a pressurized condition.

A line 77, connecting the line 39, extends to the inlet port ofa two-way bleed valve 76, normally held closed by a supplementary safety means, illustrated in FIGS. 1 and 5 as a frame 72-73-74-75, having rigid arms and 71, which supplementary safety means will be described more completely later, and the exhaust port of the two-way bleed valve 76 is preferably equipped with a muffler or silencer.

Another circuit, leading from the pressure regulator 31, supplies regulated fluid pressure through lines 41 and 42, to the respective inlet ports of the pair of threeway, normally closed manually operated valves 18 and 19 comprising the respective lefthand and righthand valves heretofore mentioned. These valves which conveniently may be the three-way, normally closed type MV-5 available from Mead Specialties Company, Chicago, 111., are each equipped with mufflers or silencers in the exhaust ports thereof, and these valves are actuated by the operator pressing upon rods housed in elongated tubes 43, 44, as seen in FIG. 2, which tubes extend upwardly from the front edge of the table 16. The outlet lines 45 and 46, leading from the respective outlet or cylinder ports of the manually operable valves 18 and 19, lead to appropriate inlet ports in the body B of the master valve 40, and the connection 46 is also connected to the line 36 leading to the pilot actuator of the control valve 34, so that upon opening of the manually operated valve 19 to pressurize the line 46, the pilot actuator of the control valve 34 is pressurized via line 36.

Referring now to FIG. 4, the master valve 40, which conveniently may be the type 1868A2002 Logicair valve available from the Ross Operating Valve Company, Detroit, Mich., includes a valve body B with an interior space 50 therein communicating directly with the respective inlet ports having lines 45 and 46 connected thereto.

Mounted for reciprocation in space 50 is a pass shuttle 51 adapted to close either upon seat 52 and 53, depending upon its direction of movement. A timing orifice 54, of fixed size, leads from the space 50 to a timing chamber 55, which timing chamber has another communication thereto from a passage 57, through a check valve space 56, having a normally closed check valve 58 mounted therein and spring biased to open when the passage 57 is pressurized at a pressure greater than the pressure in the timing chamber 55, thereby to equalize the pressure in the timing chamber 55 with the pressure in passage 57.

The passage 57 communicates directly with the outlet port in the valve body B to which the line 39 is attached, and communication of the passage 57 with the exhaust port 59 in the valve body B is governed by the positioning of the head portion 61, spaced from but attached to a piston portion 60, of a three-way, normally open valve built within the valve body B of the master valve 40.

The piston portion 60 is exposed to fluid pressure in the timing chamber 55, whereas the head portion 61 is exposed to fluid pressure in passage 57. The head portion 61 is slightly larger than the passage 59a, which provides communication between the passage 57 and the exhaust port 59, and normally the head portion 61 blocks communication between the passage 57 and the exhaust port 59.

Spaced from, but adapted to be blocked by the head portion 61, when the piston 60 is operated in response to fluid pressure of a predetermined value in the timing chamber 55, is a single connecting passage 62 having two connecting branch passages 63 and 64, which branch passages communicate with the space 50 on opposite sides of the pass shuttle 51.

.A check shuttle C, having equally sized and spaced heads 65 and 66, is positioned and adapted to establish communication between the single passage 62, and one or the other, but not both simultaneously, of the branch passages 63 or 64, depending upon the positioning of the check shuttle C.

The diameter of the single passage 52, moreover, is less than the diameter of the passage 59a and the piston 60, thereby to provide a necessary area differential between the passage 62 and the piston 60.

From the foregoing it will be apparent that the function of the pass shuttle 51 is to establish pressurization of the timing chamber 55 from the first of the two lines 45 or 46, when pressurized by reason of either sequential or simultaneous operation of the two manually operable valves 18 and 19, whereas the function of the pass shuttle C is to establish pressurization of the single passage 62 from the second of the two lines 45 or 46 when pressurized by reason of either sequential or simultaneous operation of the two manually operable valves 18 and 19.

The relation of the size of the fixed timing orifice 54 to the volume of the timing chamber 55 is such as to provide pressurization of the timing chamber 55 to approximately 75 percent of the regulated inlet pressure from either of the inlet prots in the valve body B, connected by lines 45 or 46, in approximately 1 second.

The piston 60 is arranged and adapted to operate in response to the aforesaid pressurization of the timing chamber 55, when the pressure therein reaches the 75 percent level, and when the single passage 62 has not been pressurized, thereby to block the single passage 62, and to vent the passage 57, via passage 59a, to the exhaust port 59 in the valve body B.

The relative area of the single passage 62, and the piston 60, is such as to prevent an unblocking of the single passage 62 by the head portion 61, should the single passage 62 be pressurized after the piston 60 has operated.

Likewise, the relative area of the head portion 61, and the piston 60, is such as to retain blocking of the passage 59a, communicating with the exhaust port 59, as long as pressure within the passage 57 remains either greater than or equal to the pressure within the timing chamber 55.

As hereinbefore described, the check valve 58 is spring biased to permit flow of air from passages 57 to the timing chamber 55, for the purpose of equalizing pressures therein. However, the biasing of the check valve 58 is such as to prevent a flow of air from the timing chamber 55 to the passage 57.

Therefore, after pressurization of the passage 57 is effected in response to proper operation of the two manually operable valves 18 and 19, should the pressure in line 39, connecting the outlet port of the master valve 40, be reduced either intermittently or for a longer duration, the pressure in the passage 57 will be reduced, and the pressure in the timing chamber 55 will then exceed the pressure in the passage 57, which will immediately result in an operation of the piston 60 to provide blocking of the single passage 62 by the head portion 61, and to vent the passage 57 to exhaust, via passage 59a to the exhaust port 59 in the master valve 40.

Thus, the normally closed bleed valve 76 is provided to vent the line 39 to exhaust, whenever the safety means, consisting of frame members 72, 73, 74, and is operated to open the bleed valve 76.

The pass shuttle 51 and the check shuttle C, within the master valve 40, are illustrated schematically in FIG. 4 as having pressure applied to one inlet port of the master valve 40 via line 46. Since the three way, normally open valve, including the head portion 61 and the piston 60 is not operated, it may be assumed that pressure was subsequently applied to the other inlet port via line 45, before the pressure in the timing chamber 55 reached a value of approximately 75 percent of the pressure applied to the passage 57, via line 45, branch 63, and single passage 62.

Therefore, the head portion 61 is retained in its unoperated position blocking the passage 59a which passage communicates with the outlet port 59 of the master valve 40. Thus, upon pressurizing the passage 57 from the inlet port via line 45, the spring biased check valve 58 responds to the higher pressure in the passage 57 and thus allows the higher pressure to pass through the open check valve 58 into the timing chamber 55, thus equalizing the pressure applied to the head portion 61 and the piston 60.

Thereafter, as long as pressure is continuously maintained upon the lines 45 and 46, the line 39 will remain pressurized from the passage 57.

if pressureis intermittently removed from the inlet port via line 45, such as an intermittent releasing of the manually operable valve 18, the line 45 will be intermittently connected to exhaust, and thereby reduce the pressure in the passage 57 to a value substantially lower than the regulated pressure established and maintained in the timing chamber 55. Therefore, the piston 60 will immediately operate, causing the head portion 61 to block the single passage 62, and to vent the passage 57 to exhaust via passage 59a and the exhaust port 59.

A subsequent pressurization of the line 45, while the line 46 has been retained pressurized,- will re-pressurize the single passage 62, but, because of the area differential between the smaller passage 62 and the relatively larger piston 60, the piston 60 will remain operated to hold the single passage 62 blocked by the head portion 61, and the passage 57 will remain vented to exhaust via passage 59a.

Likewise, if the pressure had been intermittently removed from the other inlet port of the master valve 40 via line 46, instead of the latter described operation via line 45, the reduced pressure in line 46, space 50, and branch passage 64, would result in the pass shuttle 51 and the cheek shuttle C each shifting to the right, thus maintaining pressure in the timing chamber 55 via timing orifice 54, and line 45. The pressure in the branch passage 64, single passage 62, and the passage 57 would then be reduced by reason of the lower pressure in line 46. Therefore, the piston 60 would immediately operate, causing the head portion 61 to block the single passage 62, and to vent the passage 57 to exhaust'via passage 59a and the exhaust port 59.

As aforesaid, re-pressurization of the line 46, while line 45 is retained pressurized, will re-pressurize the single passage 62, but, because of the area differential between the smaller passage 62 and the relatively larger piston 60, the piston 60 will remain operated to hold the single passage 62 blocked by the head portion 61, and the passage 57 vented to exhaust via passage 59a.

Therefore, before the master valve 40 can again be operated via lines 45 and 46, both of the manually operable valves 18 and 19 must be released, and thus vent each of the respective lines 45 and 46 to exhaust. This will permit restoration of the piston 60 to the position illustrated in FIG. 4, and to permit pressurization of the single passage 62 and the passage 57, by sub sequently operating the two manually operable valves 18 and 19 either simultaneously, or within 1 second of one another.

With reference to FIG. 3, it will be apparent that when the outlet port of the master valve 40 is connected to exhaust within the valve, by reason of the operator releasing the left hand valve 18, the control valve 34 is retained operated from the righthand valve 19, thus resulting in the exhausting of the pilot actuator 33 of the main valve 32 via the open connection through the control valve 34 from line 37 to line 39.

Likewise, if the right-hand valve 19 is released before the piston in the closing cylinder 23 reaches a position beyond the connection of line 38a thereto, the connection of line 46 to exhaust, through valve 19, will exhaust the pilot actuator 35 of the control valve 34, causing the valve 34 to block the connection from line 39 to line 37, and to open its connection from line 38 to line 37. This will connect the pilot actuator 33 of the main valve 34 to exhaust via line 38, and open connection from line 38 to line 38a within the manual detent valve 94, and by line 38a and its connection to the closing cylinder 23. However, it the right-hand valve 19 is released after the piston in the closing cylinder 23 reaches a position beyond the connection of line 38a thereto, the line 38a will receive pressure from the cylinder 23, and thus hold the pilot actuator 33 of the main valve 32 pressurized via line 380, the open connection from line 38a to line 38 within the manual detent valve 94, line 38, the open connection from line 38 to line 37 in the control valve 34, line 37, and thence to the pilot actuator 33.

This will result in a locking of the head in pressure engagement with the buck 14. Therefore, to release the locked engagement, a subsequent operation of the right-hand valve 19, will pressurize the pilot actuator 35 of the control valve 34. This will block the connection from line 37 to line 38 within the valve 34, and

open the connection from line 37 to line 39 therein.

Thus, since the line 39 is now connected to exhaust within the master valve 40, the pilot actuator 33 of the main valve 32 is exhausted.

This will return the main valve 32 to its unoperated position, thus blocking the connection from line 80a to line 80, and opening the connection from line 80 to the exhaust port of main valve 32, thereby exhausting the closing and pressure cylinders 23 and 24, in a manner to be more completely described later.

For clarity, the operation of the described master valve 40, and the associated right hand and left hand manually operated valves 18 and 19 may now be reviewed before passing to the description of the remainder of the conduit system.

Accordingly, with a first situation in which the operator first opens valve 18 with his left hand, the check shuttle C shifts to the right, and its head blocks air flow from branch passage 63 to a single passage 62. The pass shuttle 51 also shifts to the right, passing air from line 45 through the timing orifice 54 into the tiniing chamber 55, and simultaneously blocking flow from space 50 to branch passage 64. Within 1 second, air pressure in timing chamber 55 reaches its percent value which is sufficient to raise piston 60 to cause head 61 to block any flow from the single passage 62 into passage 57. At this time passage 57 is vented to the exhaust port 59 via passage 59a. If during this 1 second period, the operator opens valve 19 with his right hand, air will flow promptly, at full regulated pressure from line 46 into branch passage 64 and thence into single passage 62, whereupon it will act upon head 61 to retain passage 59a blocked and thus pressurize outlet passage 57, The full pressure in passage 57 will unseat check valve 58, causing timing chamber 55 to reach instantly full line pressure. With equal pressure applied to head 61 and to piston 60, the passage 59a remains blocked by the head 61 to block communication of outlet passage 57 with exhaust port 59 via passage 590. At this time, the outlet line 39 supplies pressure into and through the control valve 34, via lines 39 and 37, to the pilot actuator 33 of the main valve 32,'which valve is shifted to its second position for the purpose later to be described.

It is apparent that, after having served to supply fluid through line 39 to the inlet of the control valve 34, the master valve 40 requires both its inlet lines 45 and 46 to be exhausted before it is prepared for the next usage. Thus, the operator necessarily must release both of his hands to permit the manually operated valves 18, 19 to return to their respective spring biased, closed positions before starting the next operation of the press.

Taking now, as an example of improper operation, a second situation in which the operator waits more than one second before opening the right-hand valve 19, after having first opened the left-hand valve 18, it will be seen that the air pressure in the timing chamber 55 acting on the piston 60, as a result of the left-hand valve 18 having been first opened, serves to hold the head 61 in raised or closed position, blocking the single passage 62, and also to keep the check valve 58 closed. Thus the passage 57 remains vented to the exhaust port 59 via passage 59a, and no fluid is supplied through line 39 to the inlet of the control valve 34.

A third situation, in which the operator first opens valve 19 with his right hand, causes the check shuttle C to shift to the left and its head portion 66 to block air flow from branch passage 64 to the single passage 62. The pass shuttle 51 also shifts to the left, passing air from line 46 through the timing orifice 54 into the timing chamber 55, and simultaneously blocking air flow from space 50 to branch passage 63. Within 1 second, pressure in timing chamber 55 reaches its 75 percent value which is sufficient to raise piston 60 to cause head 61 to block any flow from the single passage 62 into passage 57. At this time passage 57 is vented to the exhaust port 59 via passage 59a. If during this 1 second period, the operator opens valve 18 with his left hand, air will flow promptly, at full regulated pressure, from line 45 into branch passage 63 and thence into single passage 62, whereupon it will act upon head 61 to retain passage 59a blocked and thus pressurize outlet passage 57.

The full pressure in passage 57 will unseat check valve 58, causing timing chamber 55 to reach instantly full line pressure. With equal pressure applied to head 61 and to piston 60, the passage 59a remains blocked by head 61 to block communication of outlet passage 57 with exhaust port 59 via passage 59a, and the line 39 is pressurized from outlet passage 57. As above indicated, the master valve 40 requires both of its inlet lines 45 and 46 to be exhausted before it is prepared for the next usage. Thus, the operator must release both of his hands to permit the manually operated valves 18 and 19 to return to their respective spring biased, closed positions before starting the next operation of the press.

Considering as an example of improper operation, a fourth situation in which the operator waits more than l second before opening the left-hand valve 18 after having first opened the right-hand valve 19, it will be seen that the air pressure in the timing chamber 55 acting upon the piston 60, as a result of the right-hand valve 19 having been first opened, serves to hold the head 61 in closed position blocking the single passage 62, and also to keep the check valve 58 closed. Thus the passage 57 remains vented'to the exhaust port 59 via passage 59a, and no fluid is supplied through line 39 to the inlet of the control valve 34.

As an example of properoperation, in a fifth situation, in which both the left-hand and right-hand valves 18 and 19 are opened simultaneously, the heads 65 and 66 of the check shuttle C and the pass shuttle 51, will remain in their respective positions which they occupied at the end of the previous operation of the master valve 40. Therefore, if they occupy a position with the shuttles shifted to the right, the subsequent operation will be as defined by the first above situation, and if they occupy a position shifted to the left, the subsequent operation will be as defined by the above third situation.

As will be appreciated, in the operation of the described safety means, the press cannot be operated unless air, at approximately full regulated line pressure, pressurizes the pilot actuator 33 of the main valve 32.

I therefore employ for the protection of a person other than the machine operator, a safety structure such as shown in FIGS. 1 and 5. This comprises a frame or means 72, 73, 74 and 75 surrounding the movable member 15 and occupying a predetermined position with respect thereto, note FIG. 5, so that upon its being shifted from the predetermined position, when striking an object such as a hand, etc., the movable member 15 will be released instantly, and unable to continue in its closing movement.

One suitable structure includes a rectangular frame having rigid arms 70, 71 extending rearwardly from the rear portion 72 of the frame, and pivotally attached to the movable yoke 13, preferably at the axis of rotation thereof for movement therewith. The front portion 73 and the side portions 74, 75 of the frame are so disposed that they will approach the press buck 14 in advance of the head 15. Suitably mounted on the yoke 13, for movement therewith, is a two way bleed valve 76 held in closed position by'the weight of the frame. The exhaust port of the bleed valve 76 is preferably equipped with a suitable muffler or silencer, and the inlet port is connected by line 77 to the outlet line 39 of the master valve 40. The bleed valve 76 may be a Mead Type MV-5 having its manual actuator 78 held in closed position by the arm of the frame, so long as the frame 72,73, 74 and occupies its predetermined position with respect to the yoke 13, and to the press head 15 carried by the yoke.

However, when the frame is raised relative to the yoke and head, the manual actuator 78 is released by the upward pivotalmovement of the arm 70, and the valve 76 is opened, thereby ventingthe lines 77 and 39 to exhaust, and causing the master valve 40 to shift to its position removing pressure from line 39 and venting the line 39 to exhaust through its passage 59a and exhaust port 59, as hereinbefore described in detail.

Referring now to F1GS,2 and 3, when employed with.

a garment pressing machine, the master valve 40, under any of the first, third, or fifth situations, and with the pilot actuator 35 of the control valve 34 pressurized, the pilot actuator 33 of the main control valve 32 is pressurized, thus operating the main valve 32 to its second position. As long as the line 37 is held pres surized, either from line 39, or from line 38, as hereinbefore described in detail, regulated line pressure flows into line 80 80b herein called the second conduit from line 80a. The line 80, 80b has a pressure regulator 850, included therein, for regulating the pressure therein flowing to a three way, normally closed cam valve 27, such as Type W. M. 487 available from the W.M. Cissell Manufacturing Company, Louisville, Ky.

In such garment presses it is desirable that the speed of the closing cylinder 23 be regulated; that the pressure exerted by the pressure cylinder 24 be related to the fabric of the garment being pressed; that the locking or non-locking of the press head 15, with either a light or heavier pressure engagement with buck 14, be optional with the operator; and that suitable quick exhaust devices be provided for the cylinders 23 and 24. The present invention preserves these capabilities while providing the described safety features for the operator and others present while the machine is being operated.

A line 81, herein called the first conduit, connects line v 80 to the lower end of the closing cylinder 23, below the piston therein, through a conventional Quick Exhaust 82 which may conveniently be the type EV available from Deltrol Corporation, Bellwood, Ill, and the exhaust port of the quick exhaust is preferably provided with a suitable muffler or silencer.

A flow control assembly 83 having a built-in check valve, is interposed in line 81, and the flow control is adjustable to obtain the desired speed with which the cylinder 23 moves the head 15 to its closed position. The check valve included in the flow control assembly 83, is spring biased to block air flow from line 80 to line 81, during the period in which the closing cylinder 23 is being pressurized, and to permit air flow from line 81 to line 80, when the closing cylinder 23 is exhausted through the exhaust port of the main valve 32, when said valve 32 is restored to its unoperated position.

The pressure regulator 85a included in the line 80, 80b has a handle 85, operated by the operator, to adjust pressure to be applied by the cylinder 24 upon the garment being pressed. Ordinarily, the setting of regulator 85a is made by the operator before he places his hands upon the manually operated valves 18 and 19. However, the setting of the regulator 85a may be changed, or made, by the operator after the head 15 is closed, and locked in its closed position. A bypass having a check valve 86 is connected around the pressure regulator 85a, and this check valve is spring biased to block air flow in that bypass from line 80 to line 80b, during the period in which air is flowing to the pressure cylinder 24, and to permit air flow from line 86b to line 80 in that bypass when the cylinder 24 is exhausted through the exhaust port of the main valve 32, when said valve 32 is restored to its unoperated position.

Normally, the three way, normally closed cam valve 27 vents line 90 to the exhaust port. However, when the closing cylinder 23 is pressurized, and the press head 15 is moved to a position approximately one-half inch above the buck 14, the means 25, attached to the piston rod 26, operates the cam valve 27, blocking the connection of line 90 to its exhaust port, and opening the connection of line 90 to line 80b, thereby pressurizing the cylinder 24 to a value determined by the setting ofthe pressure regulator 85a. The pressurizing air flows from line 80 through a conventional Quick Exhaust 91 which may conveniently be the Type EV- 250 also available from the Deltrol Corporation, Bellwood, UL, and the exhaust port of quick exhaust 91 is provided with a suitable muffler or silencer. I

A pressure gage 92 is mounted upon the machine, and connected via line 92a to the pressure cylinder 24, and this gage indicates to the operator the pressure to which the garment is subjected.

As hercinhefore described, when the press head 15 is moved to a position approximately onehalf inch above the buck 14, the line 38a is changed from an exhaust condition to a pressurized condition by the flow of air from the closing cylinder 23 to the line 38a. Therefore,

.if the manual detent valve 94 is set to its lock position,

blocking the connection of line 38 to the exhaust port of valve 94, and opening the connection of line 38 to line 38a, air will flow from line 38a to line 38 through the open valve 94 to the inlet connection of control valve 34. Therefore, when the control valve 34 is returned to its normally open position, blocking the connection of line 37 to line 39 and opening the connection of line 37 to line 38, air will flow through the open valve 34 to the pilot actuator 33 of the main valve 32. Thus, the operator may now remove his hands from the valves 18 and 19, first valve 18 and then valve 19, and the press head 15 will remain closed in locked engagement with the buck 14.

As hereinbefore described, when the operator subsequently operates the right-hand valve 19 momentarily, the control valve 34 is operated, and the pilot actuator 33 of the main valve 32 is exhausted via the open connection of line 37 to the line 39, which line is now vented to the exhaust port 59 of the master valve 40s The exhausting of the pilot actuator 33 restores the main valve 32 to its normally closed, first position, in

which position connection of line to line 80a is blocked, and the connection of line 80 to the exhaust port of valve 32 is opened. This-venting of line 80 to exhaust, will permit air in the closing cylinder 23 to pass in reverse flow through line 81, and thence through the check valve incorporated in the flow control 83, thento exhaust port of valve 32, and at the same time, permit any air in the pressure cylinder 24 to passinreverse flow through lines 90, 80b, and thence through the check valve 86, to the exhaust port of valve 32.

Instantly with the establishment of the aforesaid reverse flow of air from the cylinders 23 and 24, the quick exhaust 82 and 91 will respond to the reverse flow, and provide a direct venting of cylinder 23 to the exhaust port of quick exhaust 82, and a direct venting of cylinder 24 to the exhaust port of the quick exhaust 91. At this time, the press head 15 lifts, and the garment may be removed from, or placed in another position upon the buck 14.

In the operation of such presses, the operator is called upon to perform varied duties such as steaming of the garment by operation of foot pedals (not shown),

and by closing the press head one or more times.

without actually locking-in the closing cylinder 23, or without utilizing the pressure cylinder 24. The present invention permits such operations withoutjeopardizing the safety of the operator. For example, the manual detent valve, or conventional toggle type lock, nonlock valve 94, such as Humphrey type V-3-l0-22- 30-60, is interposed in the line 38 38a, in its normally open position for locking-in. If, however, the operator does not wish the closing cylinder 23 to become locked-in, he merely transfers the valve 94 to its closed position, and line 38 cannot become pressurized from line 38a. In this situation, the cylinders 23 and 24 are operable to hold the head 15 in engagement with the buck 14, either with a light or a heavier pressure, only so long as the operator keeps his hands on the two valves 18 and 19.

Furthermore, if for some reason, the operator should decide to interrupt the locking-in operation of the press head, he may accomplish this by releasing the lefthand valve 18 before releasing the righthand valve 19, and without transferring the manual detent valve from its lock" position to its non-lock position.

Likewise, if the operator should decide to interrupt the closing movement of the press head 15, before the piston in the closing cylinder 23 opens pressure communication into line 38a, he may remove either or both hands from the valves 18 and 19, and the shuttles C and 51, together with the piston 60 within the master valve 40, and will shift automatically, effecting a depressurizing of the outlet line 39, and the venting of line 39 to the exhaust port 59 of the valve 40, thereby restoring the main valve 32 to its normally closed first position in which the connection of line 80 to line 80a is blocked and the connection of line 80 to the exhaust port of valve 32 is opened. The aforesaid interruption of the closing movement of the press head 15 will occur, as described, regardless of the position of the manual detent valve 94.

In view of the above disclosure, it will be noted that the several objectives of the invention are achieved and other advantageous results obtained:

What is claimed is:

l, A fluid operated machine having cooperative members for holding a workpiece therebetween and comprising in combination, a machine actuator for closing the members upon said workpiece, a safety structure for the protection of a person other than the operator of the machine relatively movably mounted adjacent one of said members, and a valve controlled conduit system connected to a source of pressure fluid and to said machine actuator, said system including a main valve movable between a normal first position blocking the supply of fluid to said machine actuator and a second position for supplying fluid to said machine actuator, said main valve having a pilot actuator adapted, when pressurized with fluid, to move said main valve into and to hold it in said second position and, when vented, to permit return of said main valve to its first position, a control valve for controlling the pressurizing and venting of said pilot actuator, a safety means including a master valve and spaced right hand and left harid manually operable valves, said master valve being adapted to receive fluid jointly from said manually operable valves and to pass fluid into said control valve and thence to said pilot actuator of the main valve thereby to effect actuating of said machine actuator, the flow of fluid from said master valve to said control valve being initiated only when said manually operated valves are operated within a predetermined time interval of each other, and a normally closed bleed-valve adapted to be opened upon displacement of said safety structure from a predetermined safety insuring position adjacent said workpiece holding members, said bleed-valve being connected in the line between said master valve and said control valve. 

1. A fluid operated machine having cooperative members for holding a workpiece therebetween and comprising in combination, a machine actuator for closing the members upon said workpiece, a safety structure for the protection of a person other than the operator of the machine relatively movably mounted adjacent one of said members, and a valve controlled conduit system connected to a source of pressure fluid and to said machine actuator, said system including a main valve movable between a normal first position blocking the supply of fluid to said machine actuator and a second position for supplying fluid to said machine actuator, said main valve having a pilot actuator adapted, when pressurized with fluid, to move said main valve into and to hold it in said second position and, when vented, to permit return of said main valve to its first position, a control valve for controlling the pressurizing and venting of said pilot actuator, a safety means including a master valve and spaced right hand and left hand manually operable valves, said master valve being adapted to receive fluid jointly from said manually operable valves and to pass fluid into said control valve and thence to said pilot actuator of the main valve thereby to effect actuating of said machine actuator, the flow of fluid from said master valve to said control valve being initiated only when said manually operated valves are operated within a predetermined time interval of each other, and a normally closed bleed-valve adapted to be opened upon displacement of said safety structure from a predetermined safety insuring position adjacent Said workpiece holding members, said bleed-valve being connected in the line between said master valve and said control valve. 